For this reason, we focus on 2-charge states in \(D=5\)  in the D-brane formulation.
We choose the `string' profile to be circular [1]}, [2]} to achieve integrability while keeping one free parameter (the radius \(a_f\) ) that should allow to test averaging and other effects in the relevant (reduced) ensemble of micro-states. The most general profile can oscillate in 8 transverse directions. The relevant CFT is an \({\cal N}=(4,4)\)  \(\sigma \) -model with target space \((T^4)^N/S_N\)  with \(N=PW\)  that admits a marginal deformations interpolating from the `free' orbifold point (at weak coupling), whereby the theory is integrable, to the `near'-horizon limit (at strong coupling), whereby holography connects the CFT to Type IIB strings on \(AdS_3\times S^3\times T^4\) . One can replace \(T^4\)  with \(K3\)  slightly changing the description but with similar properties.
